1. Field of the Invention
The present invention generally relates to forwarding packet data from a source node to a destination node, and more particularly to forwarding data in hybrid mesh networks that incorporate multiple wireless technologies.
2. Brief Description of the Related Art
A wireless mesh network (WMN) is a wireless communication system that provides for the communication of packet data across multiple hops to anywhere in the network using a store-and-forward mechanism. WMNs typically include a plurality of nodes in which each node capable of communicating with at least one other node. In some instances, WMNs are implemented as a fixed wireless access (FWA) system capable of communicating broadband data between fixed-site communication stations which form the nodes.
Mesh networks allow for continuous connections and reconfiguration around broken or blocked data paths by ‘hopping’ from node to node until a destination node is reached. Different from the traditional spanning tree based forwarding approach, which essentially shuts down redundant links in networks, mesh networking actively uses redundant links in the network to achieve better network robustness and performance.
In Hybrid Wireless Mesh Networks (HMNs), the same network includes links of communication technologies that have very different characteristics. For example, HMNs can include various wireless communication technologies, such as Wireless LAN, Zigbee, Bluetooth, FreeSpace Optics, etc. Typically, HMNs have better network robustness and availability than WMNs in that factors that may affect one communication technology have little effect on other communication technologies. For example, in HMNs that combine both radio links and Free Space Optics Communication (FSOC) links, radio interference tends to negatively affect the radio links but has little or no effect on the FSOC links. Alternatively, fog is a common problem for FSOC links but typically does not reduce radio link communication quality.
Current data forwarding algorithms used in conventional HMNs are essentially single path forwarding algorithms that usually do not consider individual network link capacity and load. Typically, if a communication failure occurs between links, the data stream is interrupted until the algorithm finds an alternative path. In addition, nodes with multiple links of different technologies do not aggregate link bandwidths. Furthermore, being single path forwarding, current algorithms do not take advantage of the technology diversity offered by multiple link technologies.
As such, there exists a need for a multi-path forwarding technique for HMNs that factors in link technology diversity, capacity and load.